COVALENT SUBSTANCES

Question 1

THE ATOMS WITHIN MOLECULES ARE HELD TOGETHER BY VERY STRONG COVALENT BONDS; BUT THE FORCES OF ATTRACTION BETWEEN THE MOLECULES ARE (…)

Answer 1

VERY WEAK

Question 2

WHAT DOES THE WAK INTERMOLECULAR FORCES CAUSE

Answer 2

LOW MELTING AND BOILING POIUNT BECAUSE MOLECULES ARE EASILY SEPARATED

Question 3

THE MELTING AND BOILING POINT OF THE SIMPLE MOLECVULAR SUBSTANCES INCREASE AS THE (…)

Answer 3

RELATIVE MOLECULAR MASS INCREASES

Question 4

MOST MOLECULAR. SUBSTANCES ARE (…)

Answer 4

GASES OR LIQUIDS. AT ROOM TEMPERATURE- IT CAN EITHER BE A LIQUID, GAS OR AN EASILY MELTED SOLID

Question 5

COVALENT STRUCTURE IS SIMILAR TO THE GIANT IONIC STRUCTURE EXCEPT THERE ARE (…)

Answer 5

NO CHARGED IONS

Question 6

IN COVALENT STRUCTURES ALL ATOMS ARE BONDED TO EACH OTHER BY A (…)

Answer 6

STRONG COVALENT BOND

Question 7

THERE LOTS OF BONDS THIS MEANS (…)

Answer 7

IT TAKES A LOT OF ENERGY TO BREAK THEM, SO GIANT COVALENT STRUCTURES ARE SOILDS WITH A VERY HIGH MELTING AND BOILLING POINT

Question 8

THEY DO NOT (…) EVEN WHEN MOLTEN AND THEY ARE (…) IN WATER

Answer 8

CONDUCT ELECTRICITY/INSOLUBLE

Question 9

IMPORTANT EXAMPLE OF GIANT COVALENT STRUCTURE

Answer 9

DIAMOND AND GRAPHITE (MADE ONLY FROM CARBON ATOMS)

Question 10

CHARACTERISTICS OF DIAMOND

Answer 10

-MADE UP OF A NETWPRK OF CARBON ATOMS THAT EACH FORM FOUR COVALENT BONDS
-THE STRONG COVALENT BONDS TAKE LOTS OF ENERGY TO BREAK THEM
-HAS A HIGH MELTING POINT
-THE STRONG COVALENT BONDS HOLD THE ATOMS IN A VERY RIGID LATTICE STRUCTURE (ITS REALLY HARD)
-DOESNT CONDUCT ELECTRICITY (BECAUSE IT HAS NO FREE ELECTRONS OR IONS)

Question 11

CHARACTERISTICS OF GRAPHITE

Answer 11

-EACH CARBON ONLY FORMS THREE COVALENT BONDS CREATING LAYERS OF CARBON ATOMS
-LAYERS ARE WEAKLY HOLD TOGETHER BY INTERMOLECULAR FORCES (IT MAKES IT SOFT AND SLIPPERY)
-IT HAS A HIGHT MELTING POINT (BONDS IN THE LAYERS NEED LOAD OF ENERGY TO BREAK
-EACH ATOM HAS ONE ELECTRON THATS DELOCALISED (FREE) SO IT DOES NOT CONDUCT ELECTRICITY

Question 12

CHARACTERISTICS OF C60 FULLERENCE (SIMPLE MOLECULAR SUBSTANCE)

Answer 12

-ITS MOLECULES ARE HOLLOW SPHERES MADE OF 60 CARBON ATOMS
-IT DOESNT HAVE A GIANT COVALENT STRUCTURE
-ITS MOLECULES ARE NOT HELD TOGETHER BY INTERMOLECULAR FORCES (THEY CAN SLIDE OVER EACH OTHER, SOFT)
-LIKE GRAPHITE EACH CARBON HAS A DELOCALISED ELECTRON (ELECTRONS CANT MOVE BETWEEN THE MOLECULES)
-IT IS A POOR CONDUCTOR OF ELECTRICITY